A stage pin connector, also known as a grounded stage pin (GSP) or grounded pin connector (GPC), is a standard cable type for theatrical lighting in North America and in many countries in the theatre world. Uses Stage pin connectors are generally used for conducting dimmed power from a dimmer to stage lighting instruments, although occasionally they can power other equipment. Construction The first stage pin connectors had two cylindrical pins, one for line (hot) and one for neutral, arranged symmetrically in a rectangular housing. The housing was milled from a solid block of fiberglass or bakelite which may have been impregnated with asbestos for fire resistance, with a screw-on cover. Later connectors (including those currently manufactured) use molded plastic or machined phenolic resin laminate housings . These two-pin connectors were not polarized, and thus the line and neutral conductors could be exchanged depending on which way the connectors were mated. Two-pin connectors may still be found on some equipment and are often saved by electricians for wiring ungrounded fixtures (particularly practicals), though this may not be advisable from a safety standpoint. Modern stage pin connectors have incorporated a third pin for a safety ground connection and are commonly referred to as two pin and ground (2P&G) to distinguish them from their ungrounded two-pin predecessors. The ground pin is situated between the line and neutral pins and closer to the latter for 20 A connectors. This asymmetrical configuration effectively polarizes the connector ensuring that the line and neutral conductors are not exchanged in a properly wired installation. The ground pin is also longer than the other two, ensuring that the safety ground connection is made first when making a connection. All stage pin connectors have longitudinal slits in the male pins that allow for compression when inserted into the female sockets to increase friction and therefore the mechanical security of the connection. A special tool appropriately called a pin splitter may be used to expand this slit and spread the two halves of the pin to compensate for wear. A knife may be used to the same effect, but this technique risks both personal injury, damage to the connector, or ruining of the knife blade. For these reasons, a flat-head screwdriver is often used as an impromptu pin splitter. For some time Union Connector produced 2P&G connectors with a distinctive yellow cover that featured a locking tab in the ground